T-ALL - Slide 2

Smear from a 54 year old male with an acute leukemia with blasts that have T-lymphocytic markers (cytoplasmatic CD3, CD7+). This patient had leukopenia (

2.4⋅10⁹/L

Blasts

Promyelocytes

Myelocytes

Metamyelocytes

Bands

Segments

Eosinophils

Lymphocytes

Monocytes

Immunophenotype

CD117+

CD34-

HLA-DR-

MPO-

TdT-

TCR-

CD3-

cyCD3+

CD2-

CD5-

CD7+

CD19±

CD10-

CD20-

cyCD79a-

This blast population is positive for CD117. CD34, HLA-DR and TdT are negative. CD117 is commonly seen in myeloid blasts, but in this case CD13 and CD33 are negative (important myeloid markers). However, this population does express the (early) T-cell marker cyCD3, together with CD7. Other B cell, NK cell and myeloid markers were negative (not shown).

SSC

CD45

CD117

CD34

cyCD79a

MPO

CD7

CD19

CD3

cyCD3

CD20

CD10

HLA-DR

CD7

Peripheral blood

Blasts